import java.util.*;
import java.lang.Math;

public class Main {
    public static double square(double a) {
        return a * a;
    }
    
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        double a = sc.nextDouble();
        double b = sc.nextDouble();
        double c = square(b) - square(a);
        
        double answer = Math.sqrt(c);
        
        
        System.out.println(answer);
    }
}